1. Field of the Invention
This invention relates to novel human calcitonin gene related peptides (hereinafter called "h-CGRPs") useful as medicines or clinical diagnostic aids for bone metabolism and the central nervous system.
2. Discussion of the Background
h-CGRPs have been known to have an amino acid sequence represented by the following formula: ##STR2## wherein A means Asp or Asn, B stands for Val or Met and C denotes Asn or Ser, and various biological properties [Nature, 308(19), 746-748 (1984); FEBS Letters, 183(2), 403 (1985); Neuropeptides, 4, 425-434 (1984); Nature 313(3), 54-56 (1984)].
h-CGRPs are however believed to be subjected to aminopeptidase enzymolysis and hence to undergo progressive deactivation in living bodies since their N-terminal amino groups are not protected. There is thus an outstanding demand for the development of their derivatives which can withstand the enzymolysis by the enzyme and have still stronger biological activities.